Skin Material Design to Reduce Touch Temperature

1. An electronic device, comprising: a housing having a plurality of sides, each side having an interior surface and an exterior surface; electronic components contained within the housing; and a porous and thermally conductive material associated with at least one of the plurality of sides of the housing, the material having a thermal conductivity (k) and a porosity of between 10% and 70%, wherein the porosity results in a specific heat (C p ) and density (ρ) for the porous and thermally conductive material, such that a product k*ρ*C p is between 0 (J*W)/(m 4 *K 2 ) and 1,000,000 (J*W)/(m 4 *K 2 ).

2. The electronic device of claim 1 , wherein the porous and thermally conductive material comprises at least one of: a glass-based material having a thermal conductivity between 0.5-2 W/m-K, a density between 1000-2500 kg/m 3 , and a specific heat between 500-1000 J/kg-K, a metal-based material having a thermal conductivity between 300-400 W/m-K, a density between 4000-8000 kg/m 3 , and a specific heat between 200-300 J/kg-K, and a plastic-based material having a thermal conductivity may be between 0.1-0.4 W/m-K, a density between 400-1000 kg/m 3 , and a specific heat between 1900-2000 J/kg-K.

3. The electronic device of claim 2 , wherein the porosity of the glass-based material, the metal-based material, or the plastic-based material is between 30% and 50%.

4. The electronic device of claim 1 , wherein the plurality of sides are substantially planar.

5. The electronic device of claim 1 , wherein the porous and thermally conductive material comprises a layer associated with one or both of the interior surface and the exterior surface of the at least one of the plurality of sides.

6. The electronic device of claim 5 , wherein the layer has a thickness between 100 microns and 1.00 mm.

7. The electronic device of claim 1 , wherein the porous and thermally conductive material forms the at least one of the plurality of sides.

8. The electronic device of claim 7 , wherein the at least one of the plurality of sides formed of the porous and thermally conductive material has a thickness between 50 μm and 100 mm.

9. The electronic device of claim 1 , wherein the porous and thermally conductive material forms an entirety of the housing.

10. The electronic device of claim 1 , wherein heat dissipated by the electronic components creates a junction temperature at the interior surface of the at least one of the plurality of sides, and the porous and thermally conductive material is configured to maintain a surface temperature at the exterior surface of the at least one of the plurality of sides in a range between 30 C and 60 C during a steady state operation of the electronic device, and to maintain the junction temperature below a threshold level.

11. The electronic device of claim 10 , wherein the surface temperature is maintained at or near average human body temperature (37.5 C).

12. A method of operating an electronic device, comprising: generating heat in an interior of a housing of the electronic device, the housing having a plurality of sides, each side having an interior surface and an exterior surface; and conducting at least a portion of the heat generated in the interior of the housing to an environment exterior the housing, the conducting occurring through a porous and thermally conductive material associated with at least one of the plurality of sides of the housing, the material having a thermal conductivity (k) and a porosity of between 10% and 70%, wherein the porosity results in a specific heat (C p ) and density (ρ) for the porous and thermally conductive material, such that a product k*ρ*C p is between 0 (J*W)/(m 4 *K 2 ) and 1,000,000 (J*W)/(m 4 *K 2 ).

13. The method of claim 12 , wherein the porous and thermally conductive material comprises at least one of: a glass-based material having a thermal conductivity between 0.5-2 W/m-K, a density between 1000-2500 kg/m 3 , and a specific heat between 500-1000 J/kg-K, a metal-based material having a thermal conductivity between 300-400 W/m-K, a density between 4000-8000 kg/m 3 , and a specific heat between 200-300 J/kg-K, and a plastic-based material having a thermal conductivity may be between 0.1-0.4 W/m-K, a density between 400-1000 kg/m 3 , and a specific heat between 1900-2000 J/kg-K.

14. The method of claim 13 , wherein the porosity of the glass-based material, the metal-based material, or the plastic-based material is between 30% and 50%.

15. The method of claim 12 , wherein the porous and thermally conductive material comprises a layer associated with one or both of the interior surface and the exterior surface of the at least one of the plurality of sides.

16. The method of claim 12 , wherein the porous and thermally conductive material forms the at least one of the plurality of sides.

17. The method of claim 12 , wherein the porous and thermally conductive material forms an entirety of the housing.

18. The method of claim 12 , wherein the heat generated in the interior of the housing creates a junction temperature at the interior surface of the at least one of the plurality of sides, and conducting at least a portion of the heat generated in the interior of the housing comprises maintaining a surface temperature at the exterior surface of the at least one of the plurality of sides in a range between 30 C and 60 C during a steady state operation of the electronic device, and maintaining the junction temperature below a threshold level.

19. The method of claim 12 , wherein generating heat in the interior of the housing comprises dissipating heat from at least one electronic component within the housing.

20. An electronic device, comprising: means for generating heat in an interior of a housing of the electronic device, the housing having a plurality of sides, each side having an interior surface and an exterior surface; and means for conducting at least a portion of the heat generated in the interior of the housing to an environment exterior the housing, wherein the means for conducting comprises a porous and thermally conductive material associated with at least one of the plurality of sides of the housing, the material having a thermal conductivity (k) and a porosity of between 10% and 70%, wherein the porosity results in a specific heat (C p ) and density (ρ) for the porous and thermally conductive material, such that a product k*ρ*C p is between 0 (J*W)/(m 4 *K 2 ) and 1,000,000 (J*W)/(m 4 *K 2 ).

21. The electronic device of claim 20 , wherein the porous and thermally conductive material comprises at least one of: a glass-based material having a thermal conductivity between 0.5-2 W/m-K, a density between 1000-2500 kg/m 3 , and a specific heat between 500-1000 J/kg-K, a metal-based material having a thermal conductivity between 300-400 W/m-K, a density between 4000-8000 kg/m 3 , and a specific heat between 200-300 J/kg-K, and a plastic-based material having a thermal conductivity may be between 0.1-0.4 W/m-K, a density between 400-1000 kg/m 3 , and a specific heat between 1900-2000 J/kg-K.

22. The electronic device of claim 21 , wherein the porosity of the glass-based material, the metal-based material, or the plastic-based material is between 30% and 50%.

23. The electronic device of claim 20 , wherein the porous and thermally conductive material comprises a layer associated with one or both of the interior surface and the exterior surface of the at least one of the plurality of sides.

24. The electronic device of claim 20 , wherein the porous and thermally conductive material forms the at least one of the plurality of sides.

25. The electronic device of claim 20 , wherein the porous and thermally conductive material forms an entirety of the housing.

26. The electronic device of claim 20 , wherein the heat generated in the interior of the housing creates a junction temperature at the interior surface of the at least one of the plurality of sides, and the means for conducting at least a portion of the heat generated in the interior of the housing is configured to maintain a surface temperature at the exterior surface of the at least one of the plurality of sides in a range between 30 C and 60 C during a steady state operation of the electronic device, and maintain the junction temperature below a threshold level.

27. The electronic device of claim 20 , wherein the means for generating heat in the interior of the housing comprises at least one electronic component within the housing, the at least one electronic component configured to dissipate heat.

28. A housing sub-structure for an electronic device, comprising: at least one component; and a porous and thermally conductive material associated with the at least one component, the material having a thermal conductivity (k) and a porosity of between 10% and 70%, wherein the porosity results in a specific heat (C p ) and density (ρ) for the porous and thermally conductive material, such that a product k*ρ*C p is between 0 (J*W)/(m 4 *K 2 ) and 1,000,000 (J*W)/(m 4 *K 2 ).

29. The housing sub-structure of claim 28 , wherein the porous and thermally conductive material comprises at least one of: a glass-based material having a thermal conductivity between 0.5-2 W/m-K, a density between 1000-2500 kg/m 3 , and a specific heat between 500-1000 J/kg-K, a metal-based material having a thermal conductivity between 300-400 W/m-K, a density between 4000-8000 kg/m 3 , and a specific heat between 200-300 J/kg-K, and a plastic-based material having a thermal conductivity may be between 0.1-0.4 W/m-K, a density between 400-1000 kg/m 3 , and a specific heat between 1900-2000 J/kg-K.

30. The housing sub-structure of claim 29 , wherein the porous and thermally conductive material comprises a layer associated with one or more surfaces of the at least one component.

31. The housing sub-structure of claim 30 , wherein the layer has a thickness between 100 microns and 1.00 mm.

32. The housing sub-structure of claim 29 , wherein the porous and thermally conductive material forms the at least one component.

33. The housing sub-structure of claim 32 , wherein the at least one component formed of the porous and thermally conductive material has a thickness between 50 μm and 100 mm.

34. The housing sub-structure of claim 29 , wherein the porous and thermally conductive material is associated with a plurality of sides that form an entirety of a housing.

35. The housing sub-structure of claim 29 , wherein the housing sub-structure comprises a single unitary component defining a side or a plurality of sides of a housing.

36. The housing sub-structure of claim 29 , wherein the housing sub-structure comprises a plurality of components assembled to define a plurality of sides of a housing.

37. A method of making a housing sub-structure for an electronic device, said method comprising: obtaining a porous and thermally conductive material having a thermal conductivity (k) and a porosity of between 10% and 70%, wherein the porosity results in a specific heat (C p ) and density (ρ) for the porous and thermally conductive material, such that a product k*ρ*C p is between 0 (J*W)/(m 4 *K 2 ) and 1,000,000 (J*W)/(m 4 *K 2 ); and associating the porous and thermally conductive material with at least one component.

38. The method of claim 37 , wherein the porous and thermally conductive material comprises at least one of: a glass-based material having a thermal conductivity between 0.5-2 W/m-K, a density between 1000-2500 kg/m 3 , and a specific heat between 500-1000 J/kg-K, a metal-based material having a thermal conductivity between 300-400 W/m-K, a density between 4000-8000 kg/m 3 , and a specific heat between 200-300 J/kg-K, and a plastic-based material having a thermal conductivity may be between 0.1-0.4 W/m-K, a density between 400-1000 kg/m 3 , and a specific heat between 1900-2000 J/kg-K.

39. The method of claim 37 , wherein the at least one component comprise an interior surface and an exterior surface and associating the porous and thermally conductive material with the at least one component comprises applying a layer of the porous and thermally conductive material on one or both of the interior surface and the exterior surface of the at least one component.

40. The method of claim 39 , wherein the layer has a thickness between 100 microns and 1.00 mm.

41. The method of claim 37 , wherein associating the porous and thermally conductive material with the at least one component comprises forming the at least one component with the porous and thermally conductive material.

42. The method of claim 41 , wherein the at least one component formed of the porous and thermally conductive material has a thickness between 50 μm and 100 mm.

43. A skin material for a housing of an electronic device, said skin material comprising: particles of a base material processed to form a porous and thermally conductive end material having a thermal conductivity (k) and a porosity of between 10% and 70%, wherein the porosity results in a specific heat (C p ) and density (ρ) for the skin material, such that a product k*ρ*C p is between 0 (J*W)/(m 4 *K 2 ) and 1,000,000 (J*W)/m 4 *K 2 ).

44. The skin material of claim 43 , comprising one of: a glass-based material having a thermal conductivity between 0.5-2 W/m-K, a density between 1000-2500 kg/m 3 , and a specific heat between 500-1000 J/kg-K, a metal-based material having a thermal conductivity between 300-400 W/m-K, a density between 4000-8000 kg/m 3 , and a specific heat between 200-300 J/kg-K, and a plastic-based material having a thermal conductivity may be between 0.1-0.4 W/m-K, a density between 400-1000 kg/m 3 , and a specific heat between 1900-2000 J/kg-K.

45. The skin material of claim 43 , wherein the particles are sized between 100 μm and 200 μm.

46. The skin material of claim 43 , comprising a polyethylene material having a porosity between 40% and 50%, a thermal conductivity between 0.1-0.15 W/m-K, a density of about 470 kg/m 3 , and a specific heat of about 950 W/m-K.